comparison of physiological effects of two high-flow tracheal oxygen versus t-piece during spontaneous breathing trials

Conditions: Critical Care; Oxygen Therapy; Mechanical Ventilation

Summary: spontaneous breathing trials (sbt) are essential for assessing extubation tolerance, yet optimal approaches are debated. high-flow nasal oxygen offers benefits like precise oxygen delivery, flow-related positive end-expiratory pressure generation and improved lung function. while high-flow tracheal oxygen can also be used as an sbt method, it has reduced physiological effects due to bypassing the upper airway with a more open circuit. to enhance this limitation, investigators developed a modified high-flow tracheal oxygen tube with a smaller expiratory end diameter to increase expiratory resistance and airway pressure. this is a prospective randomized crossover study that aims to compare the physiological effects of standard and modified high-flow tracheal oxygen versus t-piece during sbt.

a spontaneous breathing trial (sbt) is a crucial step in the weaning and extubation process for assessing extubation tolerance. however, the optimal approach for conducting sbts remains a topic of debate. high-flow nasal oxygen has been shown to provide several physiological benefits, including precise control of the fraction of inspired oxygen, generation of flow-related positive end-expiratory pressure, increased end-expiratory lung volume, improved oxygenation, and enhanced carbon dioxide elimination. high-flow oxygen therapy can also be applied via an artificial airway as high-flow tracheal oxygen. previous studies have identified this therapy as a potential alternative for sbts. however, compared to high-flow nasal oxygen, high-flow tracheal oxygen exhibits significantly diminished physiological effects due to the bypassing of the narrow nasopharynx, glottis, and upper airway as well as a more open circuit. to address this limitation, the investigators have developed a modified high-flow tracheal oxygen tube with a reduced expiratory end tube diameter. this modification aims to create higher expiratory resistance and airway pressure, thereby simulating the physiological effects of hfnc. this study is a prospective randomized crossover physiological study designed to compare the effects of standard and modified high-flow tracheal oxygen versus t-piece during spontaneous breathing trials. key physiological parameters will be assessed, including airway pressure, end-expiratory lung volume, vital signs, oxygenation, and respiratory workload.

Eligibility criteria:
inclusion criteria: 1. mechanical ventilation for more than 24 hours 2. considered by the physicians for the readiness to wean and ready for spontaneous breathing trials exclusion criteria: 1. age younger than 18 years old 2. pregnancy 3. hemodynamic instability (mean arterial pressure \ 140 or \<60 bpm) 4. respiratory and oxygenation instability (respiratory rate \> 35bpm or oxygen saturation measured by pulse oximetry \<90%) 5. neuromuscular diseases or phrenic nerve injury 6. recent trauma or surgery to the trachea, esophagus, neck, chest, or stomach 7. pneumothorax or placement of a chest drainage 8. contraindication to electrical impedance tomography (eit) (implantable defibrillator) 9. anticipating withdrawal of life support

Keywords: high-flow tracheal oxygen t piece spontaneous breathing trial